My 2 cents: However if one likes it or not, the question is, what do you want to achieve and how are you going to do it.

You can slice up all this into parts (if it is 1 big graphic yet) and then implement the design into whatever you want to make. Normally this is already done by the designer, so the screen designer only has to assemble it out of the parts.

So i'd suggest that you probably could start out with a blank page in your favourite website editor and load the image into the background. Then you will notice, what to cut down how, to build out the elements of it you need.

But a question still stays, what do you want to achieve and how do you want to use it (say, as a "simple" page, a css template, as a cms template, ... )